Electrical measuring instrument.



W. lE. BEEDE. ELECTRICAL MEASUBING INSTRUMENT.

A APPLIUTHJN FILED APB.. 8, 1911.

IPatented Jupe 11, 1912.

ATTRNEY muren srarns PATENT orrrcn.

waarnal E. Briana, or NEWYOBK, N.' Y.

ELEcrarcAL mEasURING INSTRUMENT.

Be itknown that I, WALTER E. Briana," a

citizen of the United States, .residing in the borough of Manhattan, inthe county of New New York, haveinvented certain neW and city of New York,

' useful Improvements'in Electrical Measuring Instruments, of which the following is a specication, referencebeing had therein to the accompanying drawings, forming part thereof. j

M invention relates to electrical measuring instruments, morelparticularly portable electrical measuring instruments' such as maybe made insmall dimensions adapted to be carried in the pocket and which in general appearance resemblea: watch.

Aanong the. principal objects of my invention lare accuracy and sensitiveness of indication; durability; reliability of operation, including ,non-liability to derangement;

simplicity of construction; and inexpensiveness of manufacture. l

Other objects of my invention will hereinafter' appear.

My invention includes an armature, a pointer and a 'counterbalanca `all in one pieoe,-such as a piece of bearin pointsand to brin the armature and t e pointer into di erent parallel planes; for example,-the bent piece could with' have a portion of `U-shape transversely, thev pointer projecting from` one leg of the U and the armature from the This form of combined armature, pointer and counterbalance renders it practicable to employ a stationary arbor, which is also a feature of my invention.

My invention also includes improved means for adjusting the armature spring,

such -,as a sprlng-anchor member rotatively York and State of sheet metal stampedv 1n proper shape and bent to provide spaced" lSpecification of Letters Patent. Patented June 11 1912. Application med April s, .1911. serial No. 619,679.

partly broken away. Fig. 2 is a front view of the instrument.' Fig. 3 is an edge vieT from the right of Fig. 1 and from the left of Fig. 2 and with the casing partly broken away. Fig. 4 is an ,enlarged partial oentral vertical section as viewed from the left in Fig. 1 and from the right in Fig. 2. Fig. v5 is a detail elevation of the combined one-piece sheet metal armature, pointer and counterbalance as it appears in Fig. 2. y

The instrument illustrated in the draw? ings has an armature 1, a pointer 2 and a coun-terbalance 3 for the armature and pointer, all composed of asingle piece of bent sheet metal. The bent metal piece forming these parts has atransversely U- shaped portion which prbvides separated .bearing points or spaced pivotal points and also serves to separate or to bring into different planes the armature 1 and the pointer 2, Such U-shaped portion being extended t0 form the counterbalance 3. l

. The combined armature and pointer and counterbalance is rotatively mounted on a stationary arbor 4 rigidly projecting from -a support shown as a base plate 5 through which it passes andthe end of which is shown as upset (Fig. 4J. A combined strengthening and bearing collar- 6 surrounds the arbor 4 in contact with the base plate 5 and spaces the base of the pointer fromv the plate 5, this collar having an outwardly tapered outer surface forming a reduced bearing surface for the pointer 2. The fact that the armature, the pointer and their counterbalance are in `one piece renders it practicable to employ the rigid stationary arbor, upon which these parts, as a single piece, are loosely rotatively mounted. Thlssgreatly simplifies the construction and economizes in manufacture, and also conduces to other advantageous results presentl to appear.

T e pointer 2 is normally maintained at zero indication by a hair-spring 7 shown as connected at a point in its louter coil -With the rotative piece which includes the armature, and at its inner end is adjustably connected to the stationary arbor 4. The spring 7 is soldered to an L-shaped lug 8 'shown 'as struck up from the adjacentl side of the counterbalance 3, leaving therein a notch of the same shape as the part struck up (Figs. 1 2 and 5). At-its inner end the hair-spring 7 is secured to a spring-anchor rotatively adjustable on the arbor 4, such 'spring-anchor being shown as a split anchor-l disk 9 frictionally engaging the free end portion of the arborv outwardly from the armature 1, so as to be readily accessible for adjustment to bring the pointer 2 to the zero indication. The stationary arbor 4 renders it possible to employ this simple and convenient means forelecting the spring adjustment. "Bhe object of securing the spring 7 to the lug 8 at a distance from the end ofthe spring is to permit this point of connection to be changed' in either direction should a test vshow that the spring' is not vof proper strength.- Such. readjustment would of course be effected in the course of -manufacture, and Vwould require resoldering `of the connection. The disk 9 is tapered to provide a reduced bearing surface for the armature 1, which, `together with the pointer 2 and counterbalance 3, it retains in proper operative position on 'the arbor 4. The

pointer 2 is bent (see Figs. 3 and 4 more particularly) so as to pass out through registering arcuate slots cut in-the base plate 5 and ina suitably calibrated dial 10 immediately overlying the base plate and over which .the pointer 2 has indicating movement. f

A conductive coil 11A controls or inlinences the armature I, such coil being shown as a flattened solenoid'and the armature l.

being shown as a core for the solenoid, such core having a tapered portion concentric 'with lthe arborv 4 and enteringthe solenoid 11, andl also having a supporting portion connecting the tapered curved portion with the, adjacentside of the U-shaped counterbalance 3. The solenoid 11 is shown as held in place on the base plate 5 by Aa sheet metal strip 12 secured by small bolts. A blank for forming the one-piece combined armature and pointer and counterbalance may be stamped from a flat sheet 'of homogeneous magnetic met-al, such as iron, the magnetic properties of the pointer 2 and counterbalance 3 being negligible, chiey because of theirv neutral'location in reference' to the coil- 11,- although, of course', if necessary proper'allowance could be made forl this factor in designing the parts. p

The instrumentfis provided with acontact terminal 13 shown as extending through the annular wall of the casing andas insulated therefrom.l In using the instrument any part of the casing could be employed as the other contactl terminal, but usually a scparate contact terminal is employed having a short iexible conductor terminating in a plug adapted to be inserted in a socket .shown (by broken lines) as formed in the stein 14.I 'The electrical circuit of the instrument may be traced from theI inclosing casing through the conductive coil 11 lto the contact terminal 13, or vice versa. Startsid ing, for example, from the casing, the cir-.

cuitv leads from the base plate 5, forming a part vof the casing,fthrough a struck up standard 15, to which one terminal ofthe coil4 is soldered, through the coil 11 to the other terminal thereof soldered to a curved metal strip' 16 which isV connected, as by screw-threading, as vshown the contact terminal 13.

It is obvious that various modifications may be made 'in the construction shown in the drawings and above particularly described vvithin the my invention.

I claim:

1. An electrical measuring instrument comprising a stationary arbor, an armature and a pointer and a'counterbalance' for the (Fig. 1);, with principle `and scope of armature and for the pointer all formed in one piece and pivotally mounted on the arbor, a spring connected to such piece and armature, a splitanchor-disk frictionally.

mounted on the free end of the arbor outwardly from the rotative piece including the armature 4so as to be frictionally rotativelyadjustable on the arbor, and a spring connected to such rotative piece and also connected to the anchor-disk and arranged i to oppose theconductive coil.

4. A combined one-piece armature and pointer and counterbalance formed of asingle piece of sheet metal.

5. A combined one-piece armature and pointer and dcouiiterbalance formed" of a single piece of sheet metal and having a vportion ofLU-shaped transversesection from the opposite sides of which the armature and the pointer project, respectively.

6. A -combined one-.piece armature and pointer and counterbalance formed of asin gle piece of sheet metal and in Vwhich the counterbalance is of .U-shaped transverse section and in which the 'armature and the pointer project, respectively,'from opposite 7 An electrical measuring instrument comprising a stationary arbor, a combined onepiece armature and pointer and counterbalance formed of a single piece `of sheet pivotallyv mounted on the.

izo

-from which the pointer projects at one metal and having a transversely U-shaped portion pivotedat spaced bearing' points on the arbor and in which the pointer projects from one side and the armature from the'other side of the Ul'sh'aped portion, a conductive coil controlling the armature, and means opposing the influence of the conf ductiie coil on the armature.

8. An "electrical measuring instrument comprising a base plate, a stationary arbor rigidly projecting from the base plate` a combined one-piece armature and pointer and counter-balance formed of a single piece of sheet metal and having a transverselyl U-shaped portion pivoted on the arbor and extended to form the counterbalance axd s1 e of the U-shaped portion and the armature from the other side thereof, a conductive coil controllingthe armature, a split anchordisk frictionaliy mounted on the arbor out- Wardly from the pivoted piece which' includes the armature so as tov be frictionally rotatively adjustable on the arbor, anda spring connected to the anchor-disk and also connected to such pivoted piece andarranged to oppose `the infuence of the conductive coil on the armature.

In testimony whereof I have affixed my signature in presence of two witnesses.

WALTER E. BEEDE. Witnesses:

WM. ASHLEY ELIAS IsAAos. 

